This
response
to the thread
is a bit late as I have gone through a lot of gaskets since I wrote the above response in February last year. I eventually found that two gaskets at Home Depot work pretty well. Not perfect but pretty well. These are made by MD, called Rubber Window Seal, and you will need the XSmall one, P/N 02592. It is 1/8" tall and 3/8" wide and I use it as the center gasket. This one has vertical ridges on it, which is its short coming. It if was an oval, it would probably be perfect. The other gasket is also an MD Rubber Window Seal, and you will need the Medium size. P/N is 63602, it is oval, 1/4" tall and 5/16" wide. This one works quite well, if you have trouble getting a good vacuum seal, it is due to the center gasket. Hope this helps you guys!